CHANGSHA -- Seventy-three high school students were hospitalized on Monday afternoon over possible food poisoning in central China's Hunan Province, according to local authorities.

All the 73 affected students from Xingzhi Middle School in the city of Lianyuan had been sent to a local hospital by 4 p.m. after they had showed symptoms of vomiting and diarrhea. As of Monday evening, one of them was still being treated and four were under medical observation in a local hospital.

The remaining affected students have been discharged from hospital and returned to school after receiving intravenous infusion therapy, according to the Lianyuan municipal government.

Initial investigation by the municipal food and drug administration showed that spoiled rice noodles provided by the school cafeteria were to blame for the incident.

Further investigation is ongoing.